The present invention is directed to a process for forming metallic copper of blister quality from copper-bearing material. The blister copper is readily transformed into anode copper.
The injection of oxygen and an aqueous cupriferous slurry into a smelting furance where they are directed toward a molten bath of cupriferous material maintained at a temperature of 2100.degree. to 2400.degree. F. to produce metallic copper is disclosed in the parent application, Ser. No. 827,359, mentioned above. This method of copper smelting can be referred to as the oxygen-slurry process. The basic concept of the oxygen-slurry process is the continuous production of metallic copper autogenously from the cupriferous material of the slurry. The process of the aforesaid application depends on the presence in the slurry or in the bath of sufficient sulfidic copper material to maintain by its oxidation the necessary high bath temperature. The process is described in the application, therefore, as involving the presence in the slurry of sufficient copper concentrates (copper sulfides) or the presence in the bath of sufficient matte (Cu.sub.2 S+FeS) or both, to develop and maintain the necessary bath temperature by oxidation of the sulfidic material.
Not all cupriferous feed materials which may be used to produce copper are adequately sulfidic for this process. For example, if the cupriferous material present in the feed slurry is cold solidified white metal (substantially pure Cu.sub.2 S) or high-grade copper concentrates or solidified matte (containing relatively little iron sulfides), or cement copper precipitates (impure metallic copper precipitated on scrap iron) there will exist a heat deficiency which must be supplied by other means.
The Szekely et al U.S. Pat. No. 3,796,568 describes a process for flame smelting of cement copper precipitates by forming a slurry of such precipitates in a liquid hydrocarbon fuel, and injecting such slurry through a burner into a combustion chamber wherein the fuel is burned, impurities are oxidized or vaporized, and the copper is melted. The copper is collected in a pool at the base of the combustion chamber. It should be noted that the Szekely et al teaching does not contemplate incorporation of the fuel into an aqueous slurry, or directing such slurry against a molten cupriferous bath at high velocity so as to effect smelting within the bath.